King Christian I had 3 000 Danish troops and 2,000 allied Germans. Sture had only about 400 troops in his army, and the Danish could easily pick a fight. In late July 1471, the fleet of 76 Danish Ships with the 5,000 troops set out from Copenhagen harbor to land in southern Sweden. Sture and Nils Bosson Sture went to central Sweden to gather as much men they could for the defense of Stockholm. The Danish fleet would have to face the murderous flow of the archipelago that blocked off Stockholm, but managed, possibly with the help of a hired Swedish pilot, to anchor between Käpplingeholm and Wolf's Island (Vargö) just across the water from Stockholm Castle. Christian decided that a siege would take too long, so he landed in southern Sweden instead. Sten Sture awaited the Danes, now with 10,000 levied peasants.

On Thursday, October 10, Sten Sture and Nils Bosson Sture lead their troops north to the area which is Hötorget in Stockholm today, near Brunkeberg after which the battle was named. Sten Sture's battle plan was to trap Christian's troops in a vice; Sten would attack from the west, Nils from the east, and Knut Posse would strike out from the city itself.

Nils flanked Christian's Army, and delivered a knockout blow. In Sten's sector, he kept on charging again and again, and managed to break through. In the ensuing battle, Christian was hit in the face by musket fire. Losing several teeth, he was forced to retire from battle. The decisive turn of battle in favor of Sture's side occurred when Nils' troops broke out of the forest north of the ridge, as Posse's troops attacked from the city. This cut off a contingent of Danish troops at the Klara monastery north of the town. Posse was killed when a German or Danish soldier hit his head with an axe. However, the Danish were in retreat. Christian retired with his troops towards the island of Käpplingen (today the Blasieholmen peninsula). However, Sten's troops destroyed the makeshift bridge Christian's troops had built, causing many to drown. The battle ended a victory for Sten Sture.

Sture's victory over Christian meant his power as viceroy of Sweden was secure and would remain so for the rest of his life. According to legend, Sture had prayed to Saint George before the battle. He later paid tribute to George by commissioning a statue of Saint George and the Dragon carved by the Lübeck sculptor Bernt Notke for the Storkyrkan church in Stockholm, as an obvious allegory of Sture's battle against Christian. An altar dedicated to George was also built in the church.

Now that Christian's invasion was beaten off, Sture had cemented Swedish freedom. He had defeated the Kalmar Union, and Sweden had gained independence. Christian's Denmark still held Iceland, Denmark, and Norway after the war. The two nations that were formed were Sweden and Denmark–Norway. Margaret of Denmark, Queen of Scotland died in 1486, Christian in 1481, and Sture in 1503.[1]